详解Java中Duration类的使用方法
目录
- 简介
- Duration和Period
- 创建方法
- 通过时间单位创建
- 通过LocalDateTime或LocalTime
- 通过已有的Duration
- 解析方法
- 用法说明
- 详解
- 比较方法
- 增减方法
- 转换单位
- 取值方法
简介
本文用示例介绍java的Duration的用法。
Duration和Period
说明
Duration类通过秒和纳秒相结合来描述一个时间量,最高精度是纳秒。时间量可以为正也可以为负,比如1天(86400秒0纳秒)、-1天(-86400秒0纳秒)、1年(31556952秒0纳秒)、1毫秒(0秒1000000纳秒)等。
Period类通过年、月、日相结合来描述一个时间量,最高精度是天。时间量可以为正也可以为负,例如2年(2年0个月0天)、3个月(0年3个月0天)、4天(0年0月4天)等。
这两个类是不可变的、线程安全的、最终类。都是JDK8新增的。
Period用法
见:详解Java中Period类的使用方法
创建方法
通过时间单位创建
基于天、时、分、秒、纳秒创建。
ofDays(), ofHours(), ofMillis(), ofMinutes(), ofNanos(), ofSeconds()。例如:
Duration fromDays = Duration.ofDays(1);
通过LocalDateTime或LocalTime
通过LocalDateTime或者LocalTime 类,然后使用between获取创建Duration。
LocalDateTime start = LocalDateTime.of(2022, 1, 1, 8, 0, 0); LocalDateTime end = LocalDateTime.of(2022, 1, 2, 8, 30, 30); Duration duration = Duration.between(start, end);
通过已有的Duration
Duration du1 = Duration.ofHours(10); Duration duration = Duration.from(du1);
解析方法
用法说明
用法示例
Duration fromChar1 = Duration.parse("P1DT1H10M10.5S"); Duration fromChar2 = Duration.parse("PT10M");
格式说明
采用ISO-8601时间格式。格式为:PnYnMnDTnHnMnS (n为个数)
例如:P1Y2M10DT2H30M15.03S
P:开始标记
1Y:一年
2M:两个月
10D:十天
T:日期和时间的分割标记
2H:两个小时
30M:三十分钟
15S:15.02秒
详解
1."P", "D", "H", "M" 和 "S"可以是大写或者小写(建议大写)
2.可以用“-”表示负数
示例大全
"PT20.345S" -- parses as "20.345 seconds"
"PT15M" -- parses as "15 minutes" (where a minute is 60 seconds)
"PT10H" -- parses as "10 hours" (where an hour is 3600 seconds)
"P2D" -- parses as "2 days" (where a day is 24 hours or 86400 seconds)
"P2DT3H4M" -- parses as "2 days, 3 hours and 4 minutes"
"P-6H3M" -- parses as "-6 hours and +3 minutes"
"-P6H3M" -- parses as "-6 hours and -3 minutes"
"-P-6H+3M" -- parses as "+6 hours and -3 minutes"
源码:
public final class Duration implements TemporalAmount, Comparable<Duration>, Serializable { //其他代码 //----------------------------------------------------------------------- /** * Obtains a {@code Duration} from a text string such as {@code PnDTnHnMn.nS}. * <p> * This will parse a textual representation of a duration, including the * string produced by {@code toString()}. The formats accepted are based * on the ISO-8601 duration format {@code PnDTnHnMn.nS} with days * considered to be exactly 24 hours. * <p> * The string starts with an optional sign, denoted by the ASCII negative * or positive symbol. If negative, the whole period is negated. * The ASCII letter "P" is next in upper or lower case. * There are then four sections, each consisting of a number and a suffix. * The sections have suffixes in ASCII of "D", "H", "M" and "S" for * days, hours, minutes and seconds, accepted in upper or lower case. * The suffixes must occur in order. The ASCII letter "T" must occur before * the first occurrence, if any, of an hour, minute or second section. * At least one of the four sections must be present, and if "T" is present * there must be at least one section after the "T". * The number part of each section must consist of one or more ASCII digits. * The number may be prefixed by the ASCII negative or positive symbol. * The number of days, hours and minutes must parse to an {@code long}. * The number of seconds must parse to an {@code long} with optional fraction. * The decimal point may be either a dot or a comma. * The fractional part may have from zero to 9 digits. * <p> * The leading plus/minus sign, and negative values for other units are * not part of the ISO-8601 standard. * <p> * Examples: * <pre> * "PT20.345S" -- parses as "20.345 seconds" * "PT15M" -- parses as "15 minutes" (where a minute is 60 seconds) * "PT10H" -- parses as "10 hours" (where an hour is 3600 seconds) * "P2D" -- parses as "2 days" (where a day is 24 hours or 86400 seconds) * "P2DT3H4M" -- parses as "2 days, 3 hours and 4 minutes" * "P-6H3M" -- parses as "-6 hours and +3 minutes" * "-P6H3M" -- parses as "-6 hours and -3 minutes" * "-P-6H+3M" -- parses as "+6 hours and -3 minutes" * </pre> * * @param text the text to parse, not null * @return the parsed duration, not null * @throws DateTimeParseException if the text cannot be parsed to a duration */ public static Duration parse(CharSequence text) { ...... } }
比较方法
比较两个时间的差
Instant start = Instant.parse("2017-10-03T10:15:30.00Z"); Instant end = Instant.parse("2017-10-03T10:16:30.00Z"); // start - end Duration duration = Duration.between(start, end); // 任何一个时间单元为负数,则返回true。true:end早于start duration.isNegative(); Duration.between(start, end).getSeconds(); Duration.between(start, end).getNano();
增减方法
plusX()、minusX()
X表示days, hours, millis, minutes, nanos 或 seconds
Duration duration = Duration.ofHours(2); Duration newDuration = duration.plusSeconds(33);
plus()/minus()方法
带TemporalUnit 类型参数进行加减:
Duration duration = Duration.ofHours(2); Duration newDuration = duration.plus(33, ChronoUnit.SECONDS);
转换单位
可以用toX来转换为其他单位,支持:toDays, toHours, toMinutes, toMillis, toNanos
Duration duration = Duration.ofHours(2); duration.toDays(); // 0 duration.toHours(); // 2 duration.toMinutes(); // 120 duration.toMillis(); // 7200000 duration.toNanos(); // 7200000000000
取值方法
可以用getX来获得指定位置的值,因为Duration是由秒和纳秒组成,所以只能获得秒和纳秒:
Duration duration = Duration.ofHours(2); duration.getSeconds(); //7200 duration.getNano(); //
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